Kekulé's working-out of the structure of benzene is a well-known story. What's forgotten is that this wasn't the first time Kekulé had dreamed a breakthrough. He discovered the tetravalent nature of carbon, the foundation of structural organic chemistry; but he did not make this 1858 breakthrough by experimentation alone. He dreamed it! As he described in a speech given at the Deutsche Chemische Gesellschaft (German Chemical Society):

"I fell into a reverie, and lo, the atoms were gamboling before my eyes! Whenever, hitherto, these diminutive beings had appeared to me, they had always been in motion; but up to that time, I had never been able to discern the nature of their motion. Now, however, I saw how, frequently, two smaller atoms united to form a pair; how a larger one embraced the two smaller ones; how still larger ones kept hold of three or even four of the smaller; whilst the whole kept whirling in a giddy dance. I saw how the larger ones formed a chain, dragging the smaller ones after them, but only at the ends of the chain. . . The cry of the conductor: "Clapham Road," awakened me from my dreaming; but I spent part of the night in putting on paper at least sketches of these dream forms. This was the origin of the Structural Theory."

Seven years later, the more famous incident occurred: a dream in which he realized that the benzene molecule had a circular structure, not a linear one like other organic compounds known at the time.

"...I was sitting writing on my textbook, but the work did not progress; my thoughts were elsewhere. I turned my chair to the fire and dozed. Again the atoms were gamboling before my eyes. This time the smaller groups kept modestly in the background. My mental eye, rendered more acute by the repeated visions of the kind, could now distinguish larger structures of manifold conformation; long rows sometimes more closely fitted together all twining and twisting in snake-like motion. But look! What was that? One of the snakes had seized hold of its own tail, and the form whirled mockingly before my eyes. As if by a flash of lightning I awoke; and this time also I spent the rest of the night in working out the consequences of the hypothesis."

SOURCE

From Serendipity : Accidental Discoveries in Science, by R.M. Roberts

EDITOR'S NOTE

I've posted this story (and other examples of scientific and technical innovations triggered by dreams) to counter a myth I've run across among skeptics. It runs something like this:

Dreams just can't do science; the only example you ever hear of is Kekulé and the benzene ring, and he didn't really dream that; it was just a daydream.

Now Kekulé's account of his "dreams" is admittedly florid and imprecise; it's not clear if he slept or was just in a deep reverie (though he later called these "dreams" and surely he ought to know best). But in many other cases, there is no such uncertainty. Agassiz's dream correctly predicting the structure of a fossil fish, Loewi's dream of an experiment to prove nerve impulses propagate chemically, Howe's dream leading to the modern sewing machine, Einstein's dream of sledding near the speed of light, Ramanujan's mathematical dreams, Parkinson's dream of the M9 fire-controller that turned the tide against the Luftwaffe--all these and more show dreams to be just as useful in hard science and technology as they unquestionably are in the arts, humanities, and soft sciences.

It is true that scientific culture discourages talk about the sources of one's creative ideas, particularly if those sources have any taint of mysticism (even though the scientific method theoretically has no problems with hypotheses coming from dreams, dice, or the Tooth Fairy; what makes it science is testing). Theoretically. But blabbing about dreams won't win you any grants!

In contrast, in the arts there's a distinct cachet to saying things like "That song/story/image came to me in a dream; I'm just channeling some mysterious spirit." If anything, it may boost your reputation.

So this notion that dreams are soft, squishy, inappropriate for science and serious research may be an artifact of reporting differences driven by economics! But don't confuse talk with behavior. I've seen no evidence that intuition and dreams play less of a role in hard science.

OK, OK. If your department head asks, we haven't had this little chat. Don't worry about it.